The present invention relates generally to phono-type plugs, in particular such as plugs for stereophonic equipment, amplifiers, video and any electrical apparatus requiring a single-ended, unbalanced plug.
Plugs of the above mentioned general type are known in the art. One of such plugs shown in FIG. 1 has a positive center pin, a ground element and a barrel. Another plug shown in FIG. 2 has a metallic barrel, and two internal elements: the solder point for the positive center pin which is an extension for the center pin, and a ground strain relief piece which is an extension from the ground and is a solder point for the ground. Its main additional function is to hold the wire in place inside the plug. FIG. 3 shows a further plug which is provided with an insulation. Still another plug is shown in FIG. 4. It includes a plastic barrel that is not screwable, in which there is no ground extension piece. The wire is soldered to the ground per se near the front end of the plug. The support to the wire inside the plug, i.e. the strain relief, is provided by the entire barrel itself. There is no ground strain relief piece. It is believed that the existing plugs can be further improved.
Accordingly, it is an object of the present invention to provide a phono-type plug which is a further improvement of the existing plugs.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a phenotype plug which has a barrel; a center pin; a ground element, an insulating element located between said barrel and said pin and having an extension adapted to support a wire and to provide a strain relief.
When the plug is designed in accordance with the present invention, the strain relief element is no longer composed of metal and therefore an unnecessary metallic component is eliminated, resulting in less attenuation of the signal, also known as less reflection. The plug is also less expensive to manufacture. Also, a higher quality of insulation is provided.
In accordance with an additional feature of the present invention the barrel can be also composed of a non-metallic material, which additionally enhances the above mentioned advantages. The quantity of the metallic material is further reduced, resulting in additional reduction of attenuation or reflection, the cost to manufacture is further reduced, and the quality of the insulation is increased.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.